Dynamo-electric machine



(No Model.) 3 Sheets-Sheet 1. E. A. SPERRY.

DYNAMO ELECTRIC MACHINE. No. 268 956- Patented Dec. 12. 1882.

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3 Sheets-Sheet 2..

(No Model.)

E. A. SPERRY.

DYNAMO ELECTRIC MACHINE. .N 0. 268,956. Patented Dec. 12, 1882..

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(No Model.)

B. A. SPERRY.

DYNAMO ELECTRIC MACHINE.

Patented Dec. 12, 1882.

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UNITED STATES ELI-TEE A. SPERRY, OF

PATENT OFFICE.

CORTLAND, NE W YORK.

DYNAMO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 268,956, dated December 12, 1882. Application filed April 28, 1881. (No model.)

1'0 all whom it may concern.-

Be it known that I, ELMER A. bPERRY, a citizen of the United States, residing at Cortland, in the county of Cortland and State of New York, have invented certain new and useful Improvements in Dynamo-Electric Machines; andI do hereby declare the following to be a-full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being bad to the accompanying drawings, and to the letters or figures ofreference marked thereon, which form a part of this specification.

My invention relates to new and useful improvements in dynamo-electric machines, and it has for its object to automatically control the current, to secure uniformity thereof, and also to secure automatically difierences in the intensity of the current generated by the machine; and it consists, first, in mounting the commutator loosely on the shaft, so that it will be free to revolve thereon through a considerable arc, its segments retaining their connections with their respective armaturecoils for the purposes hereinafter more fully do: scribed; second, in the use of flexible conductors for placing said commutator-segments in connection with theirrespectivearmature-coils, to permit of the movement of the commutator; third, in connecting the commutator to suitable mechanism, whereby its relative position is automatically controlled in response to variations in speed of rotation of the armatureshaft; fourth, in a current-regulating device connected with and controlling the commutator relative to its points of maximum and minimum current in response to variations in the intensity of an electric current; and, fifth, to so mount the commutator-brushes as to secure delicate adjustment ot'both position and pressure.

In the drawings, Figure 1 represents a side elevation of a portion of a dynamo-electric ma chine, showing the governor attached; Fig. 2, a plan view of governor, showing its mechanism; Fig. '3, a vertical sectional view of governor on line y 3 Fig. 2, showing commutator attached; Fig. 4, a side elevation of part of machine, showing current-regulating device attached; Fig. 5, a front elevation of currentregulating device; Fig. 6, a front view of retractile spring, showing mode of attachment; Fig. 7, a vertical sectional view, on line so a), Fig. 6, of retractile spring, showing commutator attached; Fig. 8, a view of commutatorbrush holder, showing mode of attachment; and Fig. 9, a side elevation of one of the coinniutor-brush clamps, showing mode of attachment in section.

Similar letters refer to like parts throughout the several views, in which- A indicates that portion of the armature which protrudes beyond the polar extensionpieces of the field, the coils of which are placed in connection with the commutator-segments by flexible radial conductors B, the connection being effected by screws I), as shown, said armature being mounted on a disk, such as described in my former application.

The commutator O is constructed of a cylindrical casting, c, bored to loosely fit the armature-shaft D, journaled in bearings D, and is provided with a flange at one end and threaded at the other to fit the nut c. Placed on the exterior of this cylinder is insulating substance 0 Against the inner surface of both flange and nut are placed rings of non-conducting substance, 0 0*, into which are cut radial grooves, equidistant and numbering the same as the coils on the armature. lnto said grooves are placed the commutator-sections, of metal, B, which are held in position by pressure exerted by nut c. To said commutator-sections are secured the flexible radial conductors B, the sections being insulated by space,or the interstices filled with non-conducting substance, which is preferable. The commutator may be made in different ways, but in every instance must be free to revolve on the armature-shaft through a considerable arc and retain its connection with the armature-coils.

Figs. 1 and 4 show the commutator-brushes mounted on standards, as shown and described in a former application. This forms no part of this invention; but the device shown in Figs. 8 and 9 is intended to apply to and forms a part of this application, and is constructed of an annular casting, E, bored to loosely lit the boss D which projects from the inner end of the bearing D, and is provided with two slotted projections, c e, which support the commutator-brush clamps F F, which are mounted loosely on rods ff and carry the commutator-brushes Gr G, said rods being provided with slots for the reception of the extremities of the springsf f which are secured to and support said clamps. The rods f f are secured to but insulated from the projections e c, the attachment being eifected by means of thumb-nuts, upon loosening of which the rods can be rotated, thus varying the pressure of the brushes or lifting them entirely from the commutator. The brush-clamps F F are provided with flexible connections 9 g, which are supported by the rods f f and placed in proper electrical connection with the machine. By means of this device the contactpoints of the brushes can be rotated on the commutator to any desired position and se cured by means of thumb-screw H, delicate adjustment being obtained by means of the right-and-left burr H and rods h h, the latter being attached to a stationary part ofjournal or base.

It is a well-known fact that the neutral points on the armature change their position as the speed of rotation of the armature-shaft varies, and it is at these points that the current should be taken from the armature. To hold the contact-points of the commutatorbrushes at that position on the commutator Which coincides with the neutral points on the armature, it becomes necessary as the speed varies to change their relative position. This is accomplished by automatically controlling the commutator by a governor, to be hereinafter described, which turns the commutator on the shaft in a direction opposite to rotation in response to said variations a distance which makes the necessary correction, brings the points coincident, and permits the brushes to collect the maximum current at all speeds.

The letter I represents the governor, which is constructed of a short cylindrical casting, 1, Figs. 2 and 3, provided with a hub,t7, bored to fit the shaft D, a set-screw being used for the purpose of attachment. In this cylinder are placed levers i 1?, each having a fulcrum atits extremity, near the periphery of the cylinder, and extending beyond the shaft on its opposite sides. These levers are provided near their free ends with adjnstably attached weights We, and at their free ends with springs t" iflwhich are secured to burrs 2' t sliding in frames cast in the cylinder, and adjustable by means of screws accessible on the exterior of said cylinder. At suitable points on the levers ing the variations in speed,which tend to pro duce corresponding variations in the relative position of the points of maximum current on the commutator and the contact-points of the commutator-brushes to hold said points coincident by an automatic movement of the commutator, hereinabove described.

When the machine is used in generating electricity for some purposes, as in plating, some forms of telegraphy, and in electric lighting by the multiple-arc incandescent system, when a corresponding resistance is not substituted on extinguishinga lamp, it is necessary to reduce the amount of current in the main circuit, with the removal of each lamp, to keep the light steady. This is eifected by an at-- tachment to the generator itself, and is con structed as follows:

On the shalt D, outside of the bearing D, is cut a thread, J, into which meshes a wormgear, J, mounted on a shaft, one end of which is provided with a cam, J in the slot of which operates the end of a lever, K. giving it an oscillating movement on its fulcrum at point It. The lowerend of said leveris forked and bears pawls L pivoted at its extremities, with their contact parts in the center, and supported above ratchets k It" by links L L, which are connected to a lever, L on opposite sides of its fulcrum. Said lever is provided nearits eX- tremity with an armature, M, and a supporting spring, m, capable of being adjusted. Above the armature M is a magnet, M, of high resistance, which is on a shunt-circuit of the machine, or on a shunt of the main circuit of a machine or machines, the field of which is maintained by this exciting-machine.

Directly under the pawls 7c 7c are the two ratcliets It ic of opposite phase, situated under their respective pawls, which are attached to a shaft, N, supported by a casting, N, and upon which is cut a thread fitted to a burr, it, having a projection bearing a fork fitted to a groove provided in the rod 0. Said rod is inserted in the shaft D, which is bored to receive it, and secured to a cross-piece, 0, projecting through a slot in the shaft. There are attached to the opposite ends of this yoke two flexible chains, P P, ofequal lengtlnwhich pass around pulleys p, and are secured to the face of the nut c of the commutator O, which is loose on the shaft and provided with a retractile spring, Q, Figs. 6 and 7, one end of which is attached to the supporting-disk of the armature, the other to a casting, B, secured to the flange of casting c of commutator. The tension of this spring is in opposition to the chains P P, the commutator being connected to the armaturecoils by the flexible conductors B.

The operation of the attachmen t is as follows: The machine being in circuit with the field of another machine larger than itself-which,for instance,is maintaining a number of incandescent lamps in multiple arc--the magnet M, of high resistance, being in a shunt of the main circuitofthe latter machine, orin the same relative position as the lamps themselves, the armature of the magnet is so adjusted by spring 1 m as to be held at point shown in the views by the magnet while it is energized by a force which indicates that the lamps in circuit are giving the proper illumination. When, however, the current strength decreases, owingto the introduction of one or more lamps or divisions, the attractive force of the magnet M also decreases,releasingthearmatureM,which, overcoming the spring at, tilts thelever L thus depressing one of the pawls H, which in its movement engages the teeth of the ratchet k turning the shalt N in direction indicated by arrow, which moves the burr it toward the front journal. This movement draws the red O and its cross-piece in the same direction,

- thus,by means of the chains and pulleys,turning the commutator on the shalt in opposition to the spring Q until the current,by so doing, is sufficiently strengthened to again causethe magnet M to hold its armature at the point indicated, at which neither of the'pawls engage their ratchets. Turning the commutator above referred to offers relatively new points of contact for the brushes, which are nearer its points of maximum current, and permits them to collect a greater amount of current. and, being used to excite the field of the larger machine, its augmentations will be attended by a corresponding increase of the intensity of thefield,which will also increase the intensity of the current generated by its armatnre,which is in the main light-circuit; but in case the commutator should be drawn too far in the above case or one or more lamps be extinguished, the magnet M would attract its armature, allowing the pawl k to engage its ratchet, which, by a motion opposite to the first, permits the retractile spring Q to move the commutator back to a position less favorablefor collecting the current,thus decreasing the main-current strength, as above described.

I do not wish to be understood as limiting myself to any particular form of regulating device, the essential features of which are in so controlling the commutator as to control the intensity of the current generated by the machine.

I am aware that a commutator adjusted by hand and provided with jointed connections for its sections has been used; but this form I do not claim.

Having thus fully described my invention, what 1 claim, and desire to secure by Letters Patent, is

1. In a dynamo-electric machine, a commatator mounted loosely on the armature-shaft, its sections retaining their connections with their respective armature-coils, in combination with means for automatically adjusting said commutator, as specified.

2. In a dynamo-electric machine, the combination of the flexible conductors with the sections of an adjustable commutator, whereby the electric connections of the sections are retained in all positions. and means, as described, for automatically adjusting the position of said commutator, as specified.

3. In a dynamo-electric machine, the centrifugal governor, as described, in combination with the movable commutator and connected with the same,wherebyits position is automatically controlled in response to variationsin the speed of rotation of the machine, substantially as specified.

4. The combination, with the movable commutator ot' a dynamo-electric machine, of a current-regulating device, substantially as described, whereby the commutator is caused to mo re, automatically on the shaft, relative to its points of maximum and minimum current, in response to variations in an electric current, substantially as described.

5. In adynamo-electric machine, the combination, with the commutator-brush clamps, of the snpporting-springsf f attached thereto, the free ends of which rest in slots provided in rods/"j", upon which the clamps are loosely mounted, whereby the pressure of the brushes can be adjusted by rotating said rods, substantially as described.

6. In a current-regulating device, the combination of the pawls k links L L, lever K, armature M, and spring on, with ratchets k is, substantially as specified.

In testimony whereof I affix my signaturein presence of two witnesses.

ELMER A. SPERRY.

Witnesses:

WILLIAM I'ITCH, J. 1%. NOTTINGHAM. 

